This invention relates to cooling systems, and more particularly, to cooling systems for utilization on vehicles where plural, different heat exchange fluids require cooling.
So-called xe2x80x9ccompact cooling systemsxe2x80x9d, especially for vehicular applications, are being investigated at an ever increasing rate. Typically, they have several heat exchangers which are positioned to define a housing. Within the housing thus defined is the impeller of a radial fan. The front of the housing is closed but includes an inlet nozzle facing the impeller and the rear wall of the housing is also closed. The impeller draws fresh air into the housing through the nozzle and expels the same radially outwardly, as cooling air, through each of the heat exchangers. Typically, the rear wall of the unit provides a journal for the impeller. Certain of the heat exchangers may be devoted to cooling the coolant of an internal combustion engine while another may be utilized to cool combustion air from the engine after it has had its pressure increased by a turbocharger or the like. Still another may be utilized as a condenser or gas cooler in an air conditioning system for the vehicle and still another may be utilized as an oil cooler for oil in vehicular systems that requires cooling, particularly, transmission oil.
One example of such an apparatus is described in European Patent Application No. [9910760.9, the entire disclosure of which is herein incorporated by reference] 99107601.9.
Other apparatus with some similar features are also shown in U.S. Pat. No. 4,202,296 and German Patent 3148942C2. The apparatus of the two identified patents do not relate to casing-like configurations as alluded to above wherein several individual cooling units are employed. Rather, they relate to so-called xe2x80x9cring-typexe2x80x9d cooling units which are more expensive to produce and consequently have not seen wide spread use as of the present. In the case of both, radial fans rotatable about a vertical axis have been employed but such a position is not particularly advantageous in terms of the efficiency of the fan.
Still another example of a ring-type cooling unit is shown in German Patent DE AS2716997 which does have the advantage of cooling several different cooling mediums. However, the cost of manufacturing a cooling system according to this patent is quite expensive.
One concern in compact cooling systems of the sort alluded to previously wherein different heat exchange fluids require cooling resides in the fact that because various ones of the heat exchangers are cooling different heat exchange fluids, to maximize efficiency, it is desired to provide only so much cooling air to each heat exchanger as is required to meet the maximum loading of the system having the heat exchange fluid which a given heat exchanger is to cool. That is, it would be desirable to balance the air flows through the respective heat exchangers according to the heat exchange capacity required of each so that excessive air flow through one or more heat exchangers not requiring that rate of air flow is avoided. Specifically, with each heat exchanger, and the associated flow of cooling air therethrough, a certain amount of fan energy will be required. Since the fans are typically driven by a mechanical connection to an internal combustion engine or by an electric motor receiving energy from a generator or alternator driven by the engine, the use of larger than needed air flows translates into increased fuel consumption which is to be avoided.
The present invention is intended to provide a means whereby air flows may be matched with the system requirements of each heat exchanger.
It is the principal object of the invention to provide a new and improved cooling system, particularly for a vehicle. More specifically, it is an object of the invention to provide a so-called compact cooling system wherein a plurality of heat exchangers are arranged to create a housing in which a radial fan is disposed and wherein the heat exchangers and the housing may be configured so that the cooling air flows through each of the plurality of different heat exchangers operating on different heat exchange fluids may be optimized to increase system efficiency.
An exemplary embodiment of the invention achieves the foregoing object in a cooling system for air cooling a plurality of at least two different heat exchange fluids. The system includes a plurality of at least three heat exchangers, each having a core with opposed ends, opposed sides extending between the ends and spaced from one another by a core width, spaced headers, one at each end of each core, and an inlet face and an outlet face spaced from one another by a core depth. The heat exchangers are arranged in adjacency in the configuration of a polygonal solid with their inlet faces located radially inward of their outlet faces and with each header in substantial abutment with a header of one of the other heat exchangers to define an open center housing. A radial fan is disposed within the housing and is rotatable about an axis. A front panel having an air inlet on the axis abuts a corresponding one of the opposed sides of each of the heat exchangers and a rear panel is provided abutting the others of the opposed sides of each of the heat exchangers as well as serving as a mounting point for journaling the fan for rotation about the axis. The core width of one of the heat exchangers is greater than that of another of the heat exchangers such that one or both of the opposed sides of the one heat exchanger projects forwardly and/or rearwardly of a corresponding one or both of the opposed sides of the other heat exchanger or heat exchangers. Thus, the inlet face area of each heat exchanger may be selected to provide a desired, and balanced air flow to minimize fan power requirements and thereby increase system efficiency.
In a preferred embodiment, the one heat exchanger has a core depth that is different from the core depth of the other heat exchanger to further assist in balancing air flow.
In a preferred embodiment, the configuration includes a top side defined by the one heat exchanger and the one heat exchanger is a charge air cooler for an internal combustion engine.
In one embodiment, the one heat exchanger projects forwardly of the air inlet on the front panel and the front panel includes a beveled surface located between the air inlet and the one of the opposed sides of the one heat exchanger abutted by the front panel.
Preferably, the one of the opposed sides is imperforate and defines part of the front panel.
A highly preferred embodiment of the invention contemplates that one or both of the front and rear panels includes a bend extending respectively to the one or to both of the opposed sides of the one heat exchanger.
Other objects and advantages will become apparent from the following specification taken in connection with the accompanying drawings.